| Message ID | 20200210193049.64362-7-keescook@chromium.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | binfmt_elf: Update READ_IMPLIES_EXEC logic for modern CPUs | expand |
On Mon, Feb 10, 2020 at 11:30:48AM -0800, Kees Cook wrote: > With arm64 64-bit environments, there should never be a need for automatic > READ_IMPLIES_EXEC, as the architecture has always been execute-bit aware > (as in, the default memory protection should be NX unless a region > explicitly requests to be executable). > > Suggested-by: Hector Marco-Gisbert <hecmargi@upv.es> > Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
diff --git a/arch/arm64/include/asm/elf.h b/arch/arm64/include/asm/elf.h index 03ada29984a7..ea9221ed68a1 100644 --- a/arch/arm64/include/asm/elf.h +++ b/arch/arm64/include/asm/elf.h @@ -105,7 +105,7 @@ * CPU*: | arm32 | arm64 | * ELF: | | | * -------------------------------|------------| - * missing GNU_STACK | exec-all | exec-all | + * missing GNU_STACK | exec-all | exec-none | * GNU_STACK == RWX | exec-stack | exec-stack | * GNU_STACK == RW | exec-none | exec-none | * @@ -117,7 +117,7 @@ * *all arm64 CPUs support NX, so there is no "lacks NX" column. * */ -#define elf_read_implies_exec(ex,stk) (stk == EXSTACK_DEFAULT) +#define compat_elf_read_implies_exec(ex, stk) (stk == EXSTACK_DEFAULT) #define CORE_DUMP_USE_REGSET #define ELF_EXEC_PAGESIZE PAGE_SIZE diff --git a/fs/compat_binfmt_elf.c b/fs/compat_binfmt_elf.c index aaad4ca1217e..3068d57436b3 100644 --- a/fs/compat_binfmt_elf.c +++ b/fs/compat_binfmt_elf.c @@ -113,6 +113,11 @@ #define arch_setup_additional_pages compat_arch_setup_additional_pages #endif +#ifdef compat_elf_read_implies_exec +#undef elf_read_implies_exec +#define elf_read_implies_exec compat_elf_read_implies_exec +#endif + /* * Rename a few of the symbols that binfmt_elf.c will define. * These are all local so the names don't really matter, but it
With arm64 64-bit environments, there should never be a need for automatic READ_IMPLIES_EXEC, as the architecture has always been execute-bit aware (as in, the default memory protection should be NX unless a region explicitly requests to be executable). Suggested-by: Hector Marco-Gisbert <hecmargi@upv.es> Signed-off-by: Kees Cook <keescook@chromium.org> --- arch/arm64/include/asm/elf.h | 4 ++-- fs/compat_binfmt_elf.c | 5 +++++ 2 files changed, 7 insertions(+), 2 deletions(-)